1. FIELD OF THE INVENTION
The present invention relates to a scarifier and, more particularly, to a scarifier whose supporting bars for claws can have their ends vertically moved so as to permit tip ends of the claws to easily follow up the irregularities of a road surface for scarifying the same to a uniform depth.
2. DESCRIPTION OF THE PRIOR ART
Conventionally, a scarifier is disposed beneath a road processing vehicle. In such a road surface layer reproducing vehicle A as shown in FIG. 6, the scarifier 1 is disposed beneath a vehicle body B and at the back of front wheels C. This scarifier 1, generally, has a suspending frame which is slender widthwise of the vehicle body when viewed from above and which can be freely raised or lowered. The suspending frame is provided with a plurality of supporting bars in such a manner that they are arranged in series in the longitudinal direction of the suspending frame. Each supporting bar has a plurality of claws fixed thereto in such a manner that they extend vertically downwardly from the supporting bar, and each supporting bar can be vertically moved while being maintained in its posture in which it is laid horizontally.
In the above-mentioned prior art scarifier, the tip end portions of the claws can be pierced into the surface layer of a road, or can be upwardly drawn off from the road surface, by vertically moving the suspending frame. That is, the tip end portions of the claws F are caused to follow up the concavities and convexities of the road surface layer G by vertically moving the supporting bar. As shown in FIG. 7 showing its front view, each supporting bar E is vertically moved while being kept in its horizontally laid posture. In addition, each claw F is fixed t the supporting bar E at right angles thereto. For these reasons, when the claw end is pierced into the road surface layer G, some claw ends H are pierced deeply while other J are pierced only to a small depth. As a result, the surface layer fails to be scarified to a uniform depth. The concavities and convexities of the road surface layer G are created by, for example, rutting. This demands an improved fluidity of an asphalt mixture constituting the road surface layer. However, repairing of the road surface layer would be much less effective unless it is performed after the layer has been scarified to a uniform depth.